Require chunk-local extraction evidence

internal/modules/dnd/validate/spells/source_refs/validator.go

@@ -15,7 +15,7 @@ import (
 const (
 	Key        = "extract/dnd/spells/source_refs"
 	ReasonCode = "invalid_source_refs"
-	policy     = "dnd.spells.validator.source_refs.v1"
+	policy     = "dnd.spells.validator.source_refs.v2"
 )
 
 type Options struct{}
@@ -33,15 +33,26 @@ func (v *Validator) CheckpointFingerprints() []pipeline.CheckpointFingerprint {
 	return []pipeline.CheckpointFingerprint{{Name: "policy", Value: policy}}
 }
 func (v *Validator) Validate(_ context.Context, req contracts.TypedValidationRequest[dnd.SpellList]) (contracts.ValidationResult, error) {
+	if req.Stage == string(pipeline.StageExtract) && req.Chunk == nil {
+		return contracts.ValidationResult{}, fmt.Errorf("spell source-reference validator requires the current extraction chunk")
+	}
 	if err := spellshape.Validate(req.Value); err != nil {
 		return contracts.ValidationResult{Approved: true}, nil
 	}
 	index := source.NewDocumentIndex(req.Source)
+	var coverage *chunkCoverage
+	if req.Stage == string(pipeline.StageExtract) {
+		coverage = newChunkCoverage(req.Chunk)
+	}
 	issues := make([]string, 0)
 	for spellIndex, spell := range req.Value.SpellCasts {
 		for refIndex, ref := range spell.SourceRefs {
 			if err := index.ValidateRef(ref); err != nil {
 				issues = append(issues, fmt.Sprintf("spell_casts[%d].source_refs[%d]: %s", spellIndex, refIndex, diagnostics.Truncate(err.Error())))
+				continue
+			}
+			if coverage != nil && !coverage.contains(req.Source, ref) {
+				issues = append(issues, fmt.Sprintf("spell_casts[%d].source_refs[%d]: source reference is outside the current extraction chunk", spellIndex, refIndex))
 			}
 		}
 	}
@@ -50,6 +61,36 @@ func (v *Validator) Validate(_ context.Context, req contracts.TypedValidationReq
 	}
 	return contracts.ValidationResult{Approved: true}, nil
 }
+
+type chunkCoverage struct {
+	sourceID string
+	unitIDs  map[int]struct{}
+}
+
+func newChunkCoverage(chunk *source.Chunk) *chunkCoverage {
+	coverage := &chunkCoverage{sourceID: chunk.SourceID, unitIDs: make(map[int]struct{}, len(chunk.Units))}
+	for _, unit := range chunk.Units {
+		coverage.unitIDs[unit.ID] = struct{}{}
+	}
+	return coverage
+}
+
+func (coverage *chunkCoverage) contains(doc *source.SourceDocument, ref source.SourceRef) bool {
+	if coverage == nil || doc == nil || ref.SourceID != coverage.sourceID {
+		return false
+	}
+	start, startOK := source.UnitIndex(doc, ref.StartUnitID)
+	end, endOK := source.UnitIndex(doc, ref.EndUnitID)
+	if !startOK || !endOK || start > end {
+		return false
+	}
+	for position := start; position <= end; position++ {
+		if _, found := coverage.unitIDs[doc.Units[position].ID]; !found {
+			return false
+		}
+	}
+	return true
+}
 func Spec() pipeline.ValidatorSpec {
 	return pipeline.ValidatorSpec{Key: Key, ExecutionClass: contracts.ExecutionClassDeterministic}
 }

internal/modules/dnd/validate/spells/source_refs/validator_test.go

@@ -48,6 +48,34 @@ func TestValidatorRejectsMissingSourceDocument(t *testing.T) {
 	}
 }
 
+func TestValidatorEnforcesCurrentChunkEvidenceDuringExtraction(t *testing.T) {
+	doc := validDocument()
+	req := requestWithValue(doc, source.SourceRef{SourceID: doc.ID, StartUnitID: 1, EndUnitID: 2})
+	req.Stage = string(pipeline.StageExtract)
+	req.Chunk = &source.Chunk{SourceID: doc.ID, Units: append([]source.SourceUnit(nil), doc.Units...)}
+	result, err := New(Options{}).Validate(context.Background(), req)
+	if err != nil || !result.Approved {
+		t.Fatalf("in-chunk extraction evidence = %#v, %v; want approval", result, err)
+	}
+
+	req.Chunk = &source.Chunk{SourceID: doc.ID, Units: []source.SourceUnit{{ID: 1}}}
+	result, err = New(Options{}).Validate(context.Background(), req)
+	if err != nil || result.Approved || !strings.Contains(result.Message, "outside the current extraction chunk") {
+		t.Fatalf("off-chunk extraction evidence = %#v, %v; want rejection", result, err)
+	}
+
+	req.Chunk = nil
+	if _, err = New(Options{}).Validate(context.Background(), req); err == nil || !strings.Contains(err.Error(), "requires the current extraction chunk") {
+		t.Fatalf("missing extraction chunk error = %v", err)
+	}
+
+	req.Stage = string(pipeline.StageNormalize)
+	result, err = New(Options{}).Validate(context.Background(), req)
+	if err != nil || !result.Approved {
+		t.Fatalf("document-wide normalization evidence = %#v, %v; want approval", result, err)
+	}
+}
+
 func TestValidatorDefersMalformedShape(t *testing.T) {
 	value := dnd.SpellList{SpellCasts: []dnd.SpellCast{{Spell: "Cure Wounds"}}}
 	result, err := New(Options{}).Validate(context.Background(), contracts.TypedValidationRequest[dnd.SpellList]{Source: validDocument(), Value: value})